The overall goal of this project is to describe secular trends in cardiovascular risk factors in the adolescent and adult U.S. population and to identify and quantify the changes in the variables related to these risk factors. A parallel goal is to modify and implement the statistical methodology available for the analysis of complex sample survey data in order to model and test these secular trends across separate nationally representative databases. The contemporaneous differences in risk factors in these nationally representative samples will be contrasted with those from a special population group, Hispanic Americans. To accomplish this goal, we will analyze data collected in nationally representative cross-sectional samples of the U.S. population to address the following 8 specific aims: 1) Describe trends in blood pressure, serum lipids and cigarette smoking in nationally representative samples of adolescents (12-17 years) and young adults (18-34 years) using data from surveys conducted from 1960 to 1984 by the National Center for Health Statistics (NCHS); 2) Describe the trends in blood pressure, serum lipids, cigarette smoking and obesity in nationally representative samples of older adults (35-75 years) using data from surveys conducted from 1960 to 1984 by NCHS; 3) Contrast the secular trends in these risk factors by subgrouping of age, race, sex, family income and educational attainment; 4) Determine the correlates of these risk factors and identify and quantify secular changes in these correlates over time; 5) Contrast contemporaneous values for risk factors and their correlates in the national population sample with the three Hispanic populations surveyed in the HHANES; In order to carry out these specific aims, we also propose to modify and refine statistical methodologies available for the analysis of complex sample survey data. These aims include 6) Implement, modify and compare recently developed statistical software for the analysis of complex sample survey data; 7) Investigate and compare alternative variational model fitting strategies to characterize the secular trends across the four national surveys; 8) Provide guidelines in the choice of analytical strategies to characterize secular trends across these nationally representative cross-sectional samples.